Pulsed electric field (PEF) has emerged as a versatile tool for influencing tissues and biomaterials, with promising applications in biotechnology, medicine, and materials science. This chapter explores the effects of electric fields on proteins, focusing on their structural, charge, and electrostatic properties. It examines forces causing linear and rotational motion of a protein in an electric field and delves into impacts on protein secondary structure and unfolding. Additionally, it also highlights how PEFs modulate peptide and protein assemblies, resulting in reversible and irreversible changes. Through selected case studies, this work offers insights into how PEFs destabilize protein structures and control self-assembly, paving the way for innovative applications in protein engineering and nonthermal processing.